For more than sixty years injectable drugs have been packed in glass vials. Such vials typically are formed of glass and have a cylindrical neck terminating in a flanged top or lip, with the opening to the interior of the vial extending through the neck. The neck is sealed by means of a rubber stopper and an aluminum seal or ferrule. When these types of vials are used in lyophilization (freeze drying) the vial is filled with liquid and then the stopper (which is a complex or complicated elastomeric member) is inserted part way into the vial so that the product can be lyophilized. In this regard, the standard stopper and vial combination often rely on a feature called a “blowback” on the inside of the vial's lip to mate with an indentation on the elastomeric stopper. This action keeps the stoppers from rising up during processing. Once the lyophilization process has occurred the stopper is then fully seated in place, e.g., pushed down, so that it is completely within the neck of the vial during the final stages of the process and a ferrule applied to lock the stopper in place to thereby permanently seal the vial. Needless to say this is a complex operation and requires that the entire operation be accomplished within sterile conditions, e.g., within the freeze drying apparatus. Moreover, the construction of the closures require the use of vials having the blowback feature, thereby limiting the materials that can be used to form the vials to glass, e.g., plastic materials have not proved economically viable for producing vials with a viable blowback feature.
Accordingly, a need exists for a capping system, particularly one that is suitable for lyophilization applications, which overcomes the drawbacks of the prior art.
The subject invention addresses that need.